L. D. Starr D. R. Dickerson H. S. Gutowsky J. Hamer G. C. Finger 1963 <p>The <span>α</span>-halogenated pyridines react with potassium fluoride in various solvents to give replacement of the <span>α</span>-halogen by fluorine. A 50% yield of 2-fluoropyridine was obtained from 2-chloropyridine by heating with potassium fluoride in dimethyl sulfone or tetramethylene sulfone for twenty-one days; 2-bromopyridine gave a similar yield with a heating period of only seven days. The <span>α</span>-halogens of the polyhalopyridines undergo the exchange reaction more readily than do the halogens of the <span>α</span>-monohalopyridines. The proposed structures of the fluoropyridines are supported by alternate syntheses and by n.m.r. studies.</p> application/pdf 10.1021/jo01041a058 en American Chemical Society Aromatic fluorine compounds. XI. Replacement of chlorine by fluorine in halopyridines article